In today networks, the interconnection between the IP/MPLS and SDH/GMPLS control plane is mostly based on the overlay model. To build it, a standard GMPLS RSVP-TE user-to-network interface (UNI) [1] has been developed at the IETF and defined as fully compliant with RSVP-TE protocol.

The GMPLS UNI enables consistent synchronization (compared to the inconsistencies introduced by other UNI implementations such as the OIF UNI) between the IP/MPLS signaling and the SDH/GMPLS signaling domains. This includes mechanisms such as (i) end-to-end explicit routing, recording and label control, (ii) end-to-end LSP association and re-routing, (iii) fast notification across UNI, (iv) LSP administrative status handling and (v) common address space.

This presentation first reviews the GMPLS RSVP-TE specific extensions in support of the end-to-end re-routing for IP/MPLS over SDH/GMPLS networks. The processing of the RSVP messages and objects is detailed at the UNI reference point. It then describes TDM LSP recovery schemes (i.e. pre-planned re-routing and dynamic re-routing using both make-before-break and break-before-make mechanisms) and the scenarios that prove their benefits in term of network resource utilization and recovery speed.

This talk then analyses the GMPLS RSVP-TE software architecture and design implemented within a prototype of a router control plane. The recovery scenarios implemented using the GMPLS RSVP-TE extensions described in [2] are detailed using functional sequence diagrams. This presentation concludes by displaying a control plane test-bed implementation that demonstrates the recovery capabilities of the GMPLS UNI.